Color images appear to the human eye as a combination of the additive primary colors of red, green, and blue. When added together in equal amounts, these colors form white light. Color images are generally more useful than black and white images as the human eye can discriminate many more shades of color than it can shades of grey. Light detectable by the human eye is only a small portion of the electromagnetic spectrum. The wavelength range represented by visible color is relatively small, from 0.4-0.7 microns. The human eye is biologically optimized for the detection of visible light. Wavelengths above and below this range must be measured using specialized instruments capable of detecting electromagnetic radiation. The electromagnetic spectrum divides this energy into specific regions that can be used by different remote sensing instruments. Infrared light is used in many diverse industrial, scientific, and medical applications. For example, night-vision devices using infrared illumination allow people to be observed without the observer being detected. However, infrared images captured by such specialized cameras lack color. Therefore, it is desirable to determine the color of pixels in an infrared image.